Lightning Gun climbing

Perhaps you didn't know, but it is existing. Even without changing knockback settings. As far as I know there are only 3 maps which use this function. Ghost-Annhilation, runmikrob-5 and one map I've forgotten the name of at the moment:

Map: runmikrob-5

All you have to do is to add a key and its value. Place the Lightning Gun where you want the player to get it and open the entity window n. Now type in "speed" into the key box, "1" into the value box and
press Return:

When you've compiled your map you should be able to climb with the Lightning Gun as good as with the Plasma Gun; even better.
I don't know if a higher value has any effect on the knockback but it didn't look like it when I tested this.